N-Aminoalkylenesulfonamido substituted monoazo colorants

ABSTRACT

This invention relates to novel mixtures consisting essentially of monoazo compounds and disazo compounds which are substituted with x (N-substituted sulfonamido) groups, to acid-addition salts of said azo compounds, useful as direct dyes particularly in the dyeing of cellulose, and to methods of preparation of said mixtures of (N-substituted sulfonamido) substituted monoazo and disazo compounds.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of copending application Ser. No. 195,118filed Oct. 8, 1980.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

This invention relates to a group of compounds classified in the fieldof chemistry and more particularly to novel monoazo and disazo compoundsuseful as direct dyes, particularly in the dyeing of cellulose; to theacid-addition salts thereof; to processes for preparing said monoazo anddisazo compounds and said acid-addition salts.

(b) Description of the Prior Art

A class of compounds known as direct dyes are known to be useful asdyeing agents for paper and fabrics. Among this group of direct dyesthere are water-soluble azo and disazo dyestuffs and their acid-additionsalts. However, heretofore known water-soluble azo and disazo dyestuffsand their acid-addition salts have suffered from a number ofdeficiencies when employed as dyes for coloring cellulose in the form ofbleached pulp of the type used for the manufacture of household papergoods such as paper napkins, paper toweling, facial tissues and soforth. Thus, they have been found to bleed undesirably out of paperproducts colored with them when the article is brought into contact withcommon household solutions, for example, water, milk, soap solutions,detergent solutions, alcoholic beverages, vinegar, rubbing alcohol andso forth. They have also been found to have relatively poorsubstantivity to bleached pulp and suffer from a low rate and degree ofexhaust from dyeing solutions containing them. They have also been foundto have a relatively poor degree of color discharge when bleached withhypochlorite or "chlorine" bleach. There is thus a need for azodyestuffs for coloring bleached pulp which have a high bleed resistance,good substantivity, both a high rate and a high degree of exhaust fromaqueous dyeing solutions in which they are utilized, and which have ahigh degree of color discharge when bleached with hypochlorite or"chlorine" bleach.

The following items to date appear to constitute the most relevant priorart with regard to the instant invention.

U.S. Pat. No. 2,863,875 (issued Dec. 9, 1958) discloses azo dyestuffscontaining the radical [--SO₂ N(R₁)(R₂ NR₃ R₄)]_(n) wherein R₁ ishydrogen or a lower alkyl, R₂ is a lower alkylene, R₃ and R₄ are loweralkyl or hydroxy lower alkyl, and n is one to eight. The products aretaught to be useful for dyeing cotton, wool, cellulose, polyamides,polyacrylics, paper and paper raw materials.

U.S. Pat. No. 3,096,322 (issued July 2, 1963) teaches monoazo dyestuffsand their precursor anilines and acetanilides bearing the radical --SO₂NHRN(R₁)₂ wherein R represents an alkylene radical having 2 or 3 carbonatoms and R₁ represents an alkyl radical having 1 to 4 carbon atoms orN(R₁)₂ collectively represents the heterocyclic piperidyl or morpholinylradicals. The azo compounds are taught to be useful for dyeing acrylicfibers.

French Pat. No. 1,253,766 (issued Apr. 11, 1960) teaches a monoazodyestuff bearing the radical ##STR1## wherein Y is an alkylene and X isa 3 or 4 carbon alkylene. The azo compounds are taught to be useful whencomplexed with cobalt or chromium for dyeing wool, silk and polyamides.

SUMMARY OF THE INVENTION

In its composition of matter aspect, the invention relates to novelmixtures of (N-substituted sulfonamido) monoazo and disazo compoundsuseful for coloring natural fibers, synthetic fiber-forming material andcellulosic materials as well as in the manufacture of paper, varnishes,inks, coatings and plastics and to the acid-addition salt forms of themixtures of N-(substituted sulfonamido) monoazo and disazo compounds.

In its process aspects, the invention relates to a process for preparingnovel mixtures of (N-substituted sulfonamido) monoazo and disazocompounds which comprises in a first step chlorosulfonating a monoazo ora disazo compound and in a second step interacting the chlorosulfonatedmonoazo or disazo compound with the appropriate alkylene diamine or(2-aminoethyl)-2-imidazolidinone.

DETAILED DESCRIPTION INCLUSIVE OF THE PREFERRED EMBODIMENTS

More specifically, this invention in the first of its composition ofmatter aspects relates to novel mixtures consisting essentially of adisazo compound which is substituted with an average of x (N-substitutedsulfonamido) groups per molecule wherein said disazo compound isselected from the group consisting of ##STR2## in which

x represents a number from 1 to 4,

Y represents a moiety selected from the class having the formulas##STR3##

R¹ represents a moiety selected from the group consisting ofalkylene-NH-alkylene-NH₂, alkylene-N-(non-tertiary C₁ to C₄ alkyl)₂,##STR4## in which alkylene represents --CH₂ CH₂ -- and --CH₂ CH₂ CH₂ --;

R² represents hydrogen, C₁ to C₃ alkyl or C₁ to C₃ alkoxy;

or the acid-addition salt forms of said disazo compounds.

In the first particular embodiment in accordance with the first of itscomposition of matter aspects, the invention sought to be patentedresides in the novel mixtures of (N-substituted sulfonamido) disazocompounds having the formula ##STR5## in which R¹, R² and x each havethe same respective meanings given in Formula II.

In a second particular embodiment in accordance with the first of itscomposition of matter aspects, the invention sought to be patentedresides in the novel mixtures of (N-substituted sulfonamido) disazocompounds having the formula ##STR6## in which R¹ and x each have thesame respective meanings given in Formula I.

In the second of its composition of matter aspects, the invention soughtto be patented resides in novel mixtures consisting essentially of amonoazo compound which is substituted with an average of x(N-substituted sulfonamido) groups per molecule wherein said monoazocompounds are of the formula ##STR7## in which

x represents a number from 1 to 4,

R represents hydrogen or the moiety ##STR8## in which R⁴ is hydrogen, C₁to C₃ alkoxy or C₁ to C₃ alkyl,

R¹ represents a moiety selected from the group consisting ofalkylene-NH-alkylene-NH₂, alkylene-N-(nontertiary C₁ to C₄ alkyl)₂,##STR9## in which alkylene represents --CH₂ CH₂ -- and --CH₂ CH₂ CH₂ --,

R³ represents hydrogen, C₁ to C₃ alkyl or C₁ to C₃ alkoxy; or theacid-addition salt forms of said monoazo compounds.

In a first particular embodiment in accordance with the second of itscomposition of matter aspects, the invention sought to be patentedresides in the novel mixtures of (N-substituted sulfonamido) monoazocompounds having the formula ##STR10## in which R¹, R³, R⁴ and x eachhave the same respective meanings given in Formula V.

In a second particular embodiment in accordance with the second of itscomposition of matter aspects, the invention sought to be patentedresides in the novel mixtures of (N-substituted sulfonamido) monoazocompounds having the formula ##STR11## in which R¹, R³ and x each havethe same respective meanings given in Formula V.

In one of its process aspects, the invention sought to be patentedresides in the process for preparing mixtures of (N-substitutedsulfonamido) disazo compounds according to Formulas I and II whichcomprises in a first step interacting an appropriate disazo compoundselected from the group having the formulas ##STR12## withchlorosulfonic acid and thionyl chloride to incorporate x molecularequivalents of the chlorosulfonyl group per molecule of disazo compoundobtaining a mixture of (chlorosulfonyl) disazo compounds, in a secondstep, interacting said mixture of (chlorosulfonyl) disazo compounds withan excess of an amine of the formula H₂ NR¹ to obtain the mixtures of(N-substituted sulfonamido) disazo compounds of Formulas I and III andin the instance where R¹ in N-[2-(2-oxo-imidazolidin-1-yl)ethyl], in athird step, the resulting mixture of[N-2-(2-oxo-imidazolidin-1-yl)ethyl]sulfonamido disazo compounds ishydrolyzed in an acid medium and, in a fourth step, the resultingmixture is rendered alkaline to obtain a mixture ofN-[N'-(2-aminoethyl)-2-aminoethyl]sulfonamido disazo compounds whereinR¹, Y and x each have the same respective meanings given in Formulas Iand II.

In a second of its process aspects, the invention sought to be patentedresides in the process for preparing a mixture of (N-substitutedsulfonamido) monoazo compounds according to Formula V which comprises ina first step interacting the appropriate monoazo compound of the formula##STR13## with chlorosulfonic acid and thionyl chloride to obtain amixture of (chlorosulfonyl substituted) monoazo compounds, in a secondstep, interacting the resulting mixture of (chlorosulfonyl substituted)monoazo compounds with an excess of an amine of the formula H₂ NR¹ toproduce a mixture of (R¹ NHSO₂ -substituted) monoazo compound and in theinstance where R¹ represents N-[2-(2-oxo-imidazolidin-1-yl)ethyl], in athird step, hydrolyzing the mixture of{N-[2-(2-oxo-imidazolidin-1-yl)ethyl]sulfonamido}monoazo compounds in astrong acidic medium and, in a fourth step, rendering the resultingmixture from the third step alkaline to obtain the mixture of{N-[N'-(2-aminoethyl)-2-aminoethyl]sulfonamido}monoazo compounds whereinR, R¹, R³ and x each have the same respective meanings given in FormulaV.

As used herein the term "C₁ to C₃ alkyl" and "C₁ to C₄ non-tertiaryalkyl" denotes saturated monovalent straight and branched aliphatichydrocarbon radicals including methyl, ethyl, propyl, isopropyl, butyl,secondary butyl and isobutyl.

The term "C₁ to C₃ alkoxy" includes saturated, acyclic, straight orbranch-chained groups such as methoxy, ethoxy, propoxy and isopropoxy.

The term "acid-addition salt" is used herein to mean that the respectiveacid molecules are present in the dyestuff molecule in the form ofacid-addition adducts. It will, of course, be understood that theprecise type of bonding will depend on the condition in which thedyestuff molecule exists, that is, as a discrete solid or dissolved insolution. Thus, in the former, it would be expected that the acidicmaterials would be bound by quaternization of primary, secondary andtertiary amino substituents of the aminoalkylenesulfonamido tail chainswhile in the latter, it would be expected although theaminoalkylenesulfonamido substituents would also be predominantly in thequaternized form, some dissociation is possible in such an "acid-base"system.

It is well known by those skilled in the art of dyestuff chemistry thatsynthetic processes for the chlorosulfonation of dyestuff moleculesalmost invariably produce mixtures of substituted products rather than asingle product having a specific number of substituents. This is, ofcourse, the case with the instant compounds. The methods ofchlorosulfonation of the monoazo and disazo dyestuffs are known andusually give mixture of chlorosulfonated products comprising, forexample, bis-, tris- and tetrachlorosulfonates. The fact that mixturesare obtained and not a single compound is not in any way deleterious tothe use of the products as dyestuffs. The procedures taught in U.S. Pat.No. 2,863,875 which have been followed to produce the requisite azosulfonic acid chloride dyestuff intermediates herein, as would beexpected have been found to produce mixtures of substituted azo dyestuffmolecules. Accordingly, the terms like zero to one, one to three, one tofive, and the like adopted in the claims and in the disclosure todescribe the number of N-substituted sulfonamido and sulfonic acidsubstituents on the subject azo dyestuffs as well as the number ofcomplexed acid molecules means the average number of said substituentsper molecule of azo dyestuff. The meaning of these terms may beillustrated with reference to the amount or number of sulfonic acidsubstituents which are introduced into the azo compounds as a result ofhydrolysis of the sulfonic acid chloride portion of the molecule bothduring isolation from its reaction mass and during the interaction ofthe sulfonic acid chloride with an appropriate amine in an aqueousmedium to obtain the desired azo sulfonamido derivative. It is obviousthat there cannot be 0.5 of a sulfonic acid substituent on the azodyestuff molecule. This figure is, of course, an average value whichresults from the presence in the mixture of azo dyestuff moleculeshaving either zero or one sulfonic acid substituent.

The instant novel acid-addition salt forms of the (N-substitutedsulfonamido) azo dyestuffs provide shades of yellow to blue-red. Theyhave valuable properties as water-soluble direct dyes useful in thedyeing art for coloring materials such as threads, sheets, filaments,textile fabrics and the like as well as in the manufacture of paper,varnishes, inks, coatings and plastics. Further, the free base forms ofthe (N-substituted sulfonamido) azo dyestuffs including theN-[2-(2-oxo-imidazolidin-1-yl)ethyl]sulfonamido derivatives are usefulas pigments and as pigment additives.

The mixtures of (N-substituted sulfonamido) azo dyestuffs and thewater-soluble acid-addition salts thereof of this invention arecharacterized by good lightfastness. The mixtures of the azo dyestuffsin the form of their water-soluble acid-addition salts are useful asdyes for dyeing operations, and in the water-insoluble free base formsas well as their acid-addition salt forms as pigments for printingoperations on woven and non-woven substrates made from natural fibers,such as wool, cellulose or linen, those made from semi-synthetic fibers,such as regenerated cellulose as represented by rayon or viscose, orthose made from synthetic fibers, such as polyaddition, polycondensationor polymerization compounds. Such dyeings or printings can be carriedout in accordance with the usual dyeing and printing processes.

The mixtures of the (N-substituted sulfonamido) azo dyestuffs and theiracid-addition salt forms of this invention are also suitable for surfacecoloring or printing paper products and cardboard as well as forcoloring paper pulps. Moreover, they are useful for incorporation intolacquers and films of various constitutions, for example, those madefrom cellulose acetate, cellulose propionate, polyvinyl chloride,polyethylene, polypropylene, polyamides, polyesters of alkyd resins. Inaddition, the subject compounds are suitable for coloring natural orsynthetic resins, for example, acrylic resins, epoxy resins, polyesterresins, vinyl resins, polystyrene resins, or alkyd resins.

The mixtures of (N-substituted sulfonamido) azo dyestuffs are readilyconverted to the corresponding water-soluble dyes by treatment in anaqueous solution containing from 0.5 to 10 equivalents of one or more ofan inorganic acid, aliphatic or hydroxyaliphatic carboxylic acid andalkanesulfonic acid selected from the group consisting of hydrochloric,hydrobromic, acetic, propionic, glycolic, 3-hydroxypropionic, lactic,methanesulfonic and ethanesulfonic acids.

The mixtures of the acid-addition salt forms can be isolated from theaqueous solution in which they are formed by techniques well known inthe art, for example, by salting out, precipitation or concentration byevaporation. However, the mixtures of water-soluble dyes thus formed arereadily utilized in the form of aqueous solutions for many of theirapplications, especially for dyeing cellulose. Accordingly, it isparticularly preferred to retain the mixtures of dyes in a concentratedaqueous solution of the type regularly employed in the paper industryfor dyeing paper products.

The acid-addition salt forms are especially valuable dyes for impartingstable yellow to blue-red shades to paper both sized and unsized. Foruse in the paper trade, the mixtures of the acid-addition salt forms ofthis invention have several outstanding advantages. Their high degree ofwater-solubility makes them particularly suitable for the preparation ofliquid dye concentrates which are preferred in the paper industry. Theuse of concentrated aqueous solutions is particularly advantageous inview of the increasing trend toward automation, since these solutionsare conveniently handled and added to the pulp slurry in accuratelymeasured amounts by means of pulp and meters. The subject aqueous dyeconcentrates are particularly suited to metered dyeing operationsbecause they have low viscosity which remains essentially unchanged overlong periods under ordinary storage conditions. Their low viscosityprovides another advantage in that they dissolve readily in the pulpslurry and prevent specking or blotching seen when more viscous dyeconcentrates are used. A further advantage of the concentrated aqueoussolution is that of convenience in shipping and handling. In shippingand its use, the high degree of solubility of the acid-addition saltforms permit handling of solutions containing a higher dye content andresults in a desirable decrease in the weight and volume of solution peramount of dye. Furthermore, the concentrated aqueous dye solutions aremore convenient for the paper mills in that the handling of dry dye,with the concomitant dusting and caking problems associated withdissolving the dye prior to its addition to the pulp slurry areeliminated.

The subject dyes constituting the mixtures of my invention are alsogenerally less prone to "bleed" than dyestuffs heretofore known whenpaper impregnated therewith is wet and placed in contact with moistwhite paper. This is a particularly desirable property for dyes designedfor coloring absorbent grade paper to be used in facial tissues,napkins, paper towels and the like wherein it can be foreseen that thecolored paper, wetted with common household liquids such as water, soapand detergent solutions, milk, carbonated and alcoholic beverages,vinegar, rubbing alcohol, and so forth, may come in contact with othersurfaces such as textiles, paper and the like which should be protectedfrom stain. Another advantageous property of these new mixtures ofwater-soluble dyes for use in the paper trade is found in their highdegree of color discharge when bleached with hypochlorite or "chlorine"bleach. This property of the mixtures of the acid-addition salt forms isparticularly desired by papermakers in order that dyed paper may becompletely bleached prior to reprocessing. Still another advantageousproperty of the mixtures of water-soluble dyestuffs of this invention isfound in their high resistance to a change of shade when used to colorcellulosic materials, which have either previously been treated with orare treated subsequent to dyeings, with wet-strength resin.

I have also found that the dyes of this invention have a high degree ofsubstantivity for bleached fiber such as is used in most coloreddisposable paper products. Moreover, they are absorbed by cellulosicfibers from aqueous solution at a very rapid rate. These properties areadvantageouse to the paper industry, because it allows the dye to beadded to the pulp just prior to formation of the sheet.

The best mode contemplated by the inventor of carrying out thisinvention will now be described as to enable any person skilled in theart to which it pertains to make and use the same.

The mixtures of disazo compounds of Formulas I and II and the mixturesof monoazo compounds of Formula V can be obtained by interacting theappropriate disazo or monoazo compound with chlorosulfonic acid andthionyl chloride to obtain the corresponding mixtures ofchlorosulfonated disazo or monoazo compound which after isolation isfurther reacted with an excess of amine of the formula H₂ HR¹ to obtainthe desired mixtures of (N-substituted sulfonamido) disazo or monoazocompounds. As an illustration, the monoazo compound(4-methoxyaniline→2-hydroxynaphthalene) was interacted withchlorosulfonic acid and thionyl chloride. The reaction is convenientlycarried out in excess chlorosulfonic acid at a temperature in the rangeof 10° to 35° C. The reaction mixture is poured onto ice and thecorresponding mixture of (chlorosulfonated) monoazo compounds areisolated by filtration. The mixture of (chlorosulfonated) monoazocompounds are interacted with an excess of1-(2-aminoethyl)-2-imidazolidinone. The reaction is conveniently carriedout in water in the presence of an alkaline carbonate, for example,potassium carbonate and an organic base, for example, pyridine at atemperature in the range of 45° to 85° C. After isolation, the resultingmixture of {N-[2-(2-oxo-imidazolidin-1-yl)ethyl]sulfonamido}monoazocompounds are hydrolyzed in a dilute aqueous acid. The hydrolysissolution is made slightly alkaline by the addition of an aqueous alkaliand the mixture of{N-[N'-(2-aminoethyl)-2-aminoethyl]sulfonamido}monoazo compounds ofFormula V or more specifically of Formula VII are isolated.

The generally known monoazo and disazo compound starting materials areidentified herein by the well known nomenclature shorthand,amine→coupling agent, for example, aniline→β-naphthol, which signifiesthe diazotized amine is coupled to the coupling agent.

The requisite monoazo and disazo compounds useful as starting materialsare known as a class in the art and are commercially available or can bereadily obtained by procedures well known in the prior art.

The requisite 1-(2-aminoethyl)imidazolidinone intermediate is a knowncompound readily obtained by procedures taught in U.S. Pat. No.2,613,212 and 2,868,727. Thus, one molecular equivalent of urea isinteracted with one molecular equivalent of diethylene triamineliberating ammonia. The reaction can be carried out neat or in thepresence of water which is distilled off during the course of thereaction. The reaction is conveniently carried out at a temperature inthe range of 100° to 250° C. The 1-(2-aminoethyl)imidazolidinone can beused directly from the reaction or it can be distilled at reducedpressure before using.

The reaction amine intermediates required for interaction with mixturesof (chlorosulfonyl) disazo and monoazo compounds to obtain the compoundsof Formulas I, II and V wherein R¹ is alkylene-N-non-tertiary-(C₁ to C₄alkyl)₂ are known compounds whose preparation is well known in the priorart. The following compounds are exemplary of these reactive aminecompounds useful in the practice of this invention.

3-Dimethylaminopropylamine

3-Diethylaminopropylamine

3-Dibutylaminopropylamine

2-Dimethylaminoethylamine

2-Diethylaminoethylamine

2-Diisopropylaminoethylamine

4-Diethylaminobutylamine

The following examples set forth the methods of preparation of themixtures of (N-substituted sulfonamido) disazo and monoazo compounds;and acid-addition salts thereof. Included in the following examples arethe results of the "bleed" tests as described in Example 1 of samples ofpaper prepared from pulp dyed with the products of the followingexamples. In these "bleed" tests the dyed sample of paper is wetted withthe appropriate household liquid and placed as a filler below clean,dry, white filter paper. After a period of time the so-called "sandwich"is disassembled and the component piece mounted and dried. The filterpapers are then examined under daylight and evaluated with respect tothe amount of dye which bled from the dyed paper sample to the filterpaper.

EXAMPLE 1

A. With stirring, 28.8 g of the red pigment(2-methoxyaniline→3-hydroxy-2-naphth-o-anisidide) was added slowly to116.0 ml of chlorosulfonic acid while maintaining 20° to 25° C. by meansof an external ice-water bath. After the resulting mixture was stirredovernight at ambient temperature, 17.7 ml of thionyl chloride was addedslowly and the reaction mixture was stirred an additional seven hours atambient temperature. The resulting solution was added slowly to amixture of 1200.0 g of ice and 400.0 ml of water with stirring. Theseparated solid was collected by filtration and washed with cold water.

B. The water wet filter cake was suspended in 150.0 ml of cold water and50.0 g of dimethylpropylamine and 2.0 ml of pyridine were added. Theresulting slurry, pH 9.6, was stirred overnight at ambient temperature,and an additional hour at 60° to 65° C. and during this hour the pHdropped to 9.2. The slurry was cooled to room temperature, flooded totwice its original volume with water and the solid collected byfiltration. The filter cake was suspended in 800.0 ml of water and thisslurry was stirred at 90° C. for approximately thirty minutes. After theslurry was cooled to ambient temperature, the solid was collected byfiltration, washed with water and dried in vacuo at 55° C. to obtain43.6 g of the mixture consisting essentially of the monoazo compoundswith an average of two dimethylaminopropylsulfonamido moieties permolecule and having the formula ##STR14##

The visible absorption spectrum of an aqueous acetic acid solution ofthis dyestuff, containing 0.02 g of dye per liter of solution showed amaximum at 508 millimicrons, A=0.409.

Paper dyed with aqueous dilutions of this concentrate had a yellow-redshade and was found to be highly bleachable in the bleach test describedhereinbelow. The dye was found to bleed only slightly from dyed paper inthe water bleed test and moderately in the soap bleed test describedhereinbelow.

DYEING PROCEDURE

A 0.1 percent stock dye solution was prepared by dissolving 1.0 g of themixture of monoazo compounds from part B above and 5.0 ml of 10 percentaqueous acetic acid to a volume of one liter with distilled water. Withstirring, 150.0 ml of the 0.1 percent dye solution was added to 100.0 gof an aqueous slurry containing approximately 3 grams of bleached kraftpulp (600 Canadian Standard Freeness). Agitation was continued forapproximately fifteen minutes prior to dilution with water to a volumeof four liters with agitation. The dyed pulp was then formed into an 8by 8 inch square of paper by means of a filter-box. The paper sheet waspressed between two blotters and then dried at 180° F. for four minutesbetween two fresh blotters to yield a uniformly dyed red-orange papersheet.

B. Sized Paper Grades:

With stirring 150.0 ml of the 0.1 percent stock dye solution was addedto 100.0 g of an aqueous slurry containing 3 grams of bleached kraftpulp (600 Canadian Standard Freeness). After approximately three minutesof stirring, 5.0 g of a 1.5 percent water solution of papermaker's alumwas added. Stirring was continued for approximately fifteen minutesbefore it was diluted to four liters with water and the pH adjusted to5.0 with dilute sulfuric acid. The dyed fiber slurry was drawn into an 8by 8 inch square of paper and dried as described in part A above.

TESTING PROCEDURES

The following test procedures were employed to determine the resistanceof the dyestuffs to bleed in moist paper, to bleed from paper in thepresence of soap or milk, and to bleaching with hypochlorite bleach.

WATER BLEED TEST

This procedure is a modification of the AATCC Standard Test Method15-1962, "Colorfastness to Perspiration."

Test pieces consisting of four plies, each one inch square, are cut fromthe dyed paper to be tested. One or more dyed papers of known dyemigration quality are included in the test series as standards.

The absorbent material consists of filter paper having a relativelysmooth finish (Whatman #1, 4.25 cm. dia. equivalent). In addition,smooth, flat, glass or clear plastic plates of adequate stiffness,measuring two inches wide and three inches long, are required asseparating plates. A 1000 gram weight serves as a dead weight loading.

Four filter paper absorbent pieces are used for each dyed paper testsquare, two for each side.

The migration test "sandwich" is constructed as follows. A separatingplate is placed on a horizontal support and two pieces of the filterpaper placed centrally on this plate with the smoother side up. Thesquare dyed paper test pieces, held by tweezers, are immersed in tapwater at room temperature for five seconds, drained for five seconds,and immediately centered on the filter paper. Immediately, two pieces offilter paper are centered on the test square and followed at once byanother separating plate. This "sandwich" is pressed for a moment withthe fingers, after which, without delay, two pieces of filter paper arepositioned on the top separating plate as before to receive a secondtest square of wetted dyed paper. The above procedure is then repeatedas rapidly as possible and without interruption, stacking one "sandwich"on the other, until all dyed paper test pieces have been put under test.

As soon as a stack is completed, a 1000 gram weight is centered on thetop separating plate. The stack is allowed to stand at room temperature(75° F.) for fifteen minutes.

At the end of the migration period, the stack is disassembled, and eachdyed paper test square and its filter paper asborbents clipped to asupporting card. A separate card is used for each test square. The dyedpaper test squares and filter papers are air dried at room temperaturefor at least two hours (in the dark) before ranking. Relative degrees ofdye migration, as compared to that from standard samples, are determinedby visual ratings, in daylight, of the intensity of dye stain on thefilter paper surfaces which had been in contact with the test square.The evaluations are graded on the basis of the following scale:

    ______________________________________                                        Bleed Grade     Definition                                                    ______________________________________                                        none            no observable bleed                                           trace           first noticeable bleed                                        slight          approximately twice the                                                       trace amount of dye bleed                                     moderate        approximately four times                                                      the trace amount of dye                                                       bleed                                                         appreciable     approximately eight times                                                     the trace amount of dye                                                       bleed                                                         much            approximately sixteen                                                         times the trace amount                                                        of dye bleed                                                  very much       approximately thirty-two                                                      times the trace amount                                                        of dye bleed                                                  ______________________________________                                    

SOAP BLEED TEST

This procedure utilizes the same method employed in the water bleed testdescribed above, except that the dyed paper test squares are immersed ina 0.5 percent tap water solution of white soap flakes (a mixture of 80percent sodium soap and 20 percent potassium soap produced from 70percent tallow and 30 percent coconut oil glyceride blend; "Ivory"brand, Proctor & Gamble Co.) at 120° F., instead of water alone.

MILK BLEED TEST

This procedure utilizes the same method employed in the water bleed testdescribed above, except that the dyed paper squares are immersed in roomtemperature homogenized milk instead of water.

BLEACH TEST

This procedure compares the degree to which the color of dyed paperswould be discharged in a waste paper recovery operation employinghydrochloric bleach.

A preliminary estimate of bleachability is obtained by placing a drop ofhypochlorite bleach, containing 2.5 percent available chlorine; on thedyed paper and allowing it to dry at room temperature. From this test,both rate and degree of bleachability are estimated.

A more accurate test, approximating paper mill procedure, is performedby defibering three grams of dyed paper in 150.0 ml of distilled waterusing a kitchen blender. The defibered pulp slurry is placed in a jarand hypochlorite is added to the extent desired, usually 2.5 percentavailable chlorine based on the weight of the dry fiber. The slurryconsisting of pulp and hypochlorite is adjusted to pH 9 with dilutesulfuric acid or dilute aqueous solution of sodium hydroxide and placedin a water bath to maintain the interval in the temperature range of115° to 125° F. After the test is started, the jar is loosely capped. Atfive minute intervals, the cap is tightened and the jar inverted twiceto circulate the liquor. The cap is loosened between inversions. Aftertwenty minutes, the pH is checked, and if higher than 7.5, is adjustedthereto. The test is then continued for an additional twenty minutes(with five minutes between inversions). The terminal pH is generallyfound to be 6.0-6.5. An excess of sodium thiosulfate is added as anantichlor, mixed for five minutes and the slurry is diluted to aconcentration of approximately 0.3 percent of fiber. Sheets are thenprepared at pH 7 without a washing step. Finally, this sheet is pressedand dried in a paper dryer. Control dyeings at specific levels can thenbe made to accurately determine the loss of strength of color onbleaching.

EXAMPLE 2

A. Under a nitrogen atmosphere, 40.6 g of the red pigment(2-methoxyaniline→2-hydroxynaphthelene) was added slowly over 15-20minutes to 400.0 g of chlorsulfonic acid maintaining 20° to 25° C. bymeans of an external cold water bath. The mixture was stirred for twohours at 20° to 31° C. After cooling to 20° C., 23.2 ml of thionylchloride was added over ten minutes. The resulting mixture was stirredfor approximately twenty-three hours and added slowly to a mixture of500.0 g of ice, 500.0 g water and 50.0 g of sodium chloride maintaininga temperature of 0° to 10° C. by the gradual addition of approximately750.0 g of ice. Following the addition of 50.0 ml of xylene, the mixturewas stirred for approximately twenty minutes at 5° to 10° C., and thesolid was collected by filtration and washed with one liter of 2 percentaqueous sodium chloride solution chilled to 5° to 10° C. to obtain 211.0g of water wet pulp containing a mixture consisting essentially of themonoazo compounds chlorosulfonated with an average of two chlorosulfonylmoieties per molecule and having the formula ##STR15##

The nuclear magnetic resonance of the chlorosulfonic acid solution ofthe dyestuff before drowning was concordant with the above structure.

B. With stirring, 72.5 g of the water wet pulp from part A directlyabove was added slowly to a mixture of 70.0 ml of water and 30.6 g ofdimethylaminopropylamine at 20° to 25° C. The mixture was stirred forapproximately two and one half hours at 20° to 25° C. and then at 60° to70° C. for approximately forty-five minutes. The pH of the mixture wasadjusted to 8.5 using 3-N-hydrochloric acid and the separated solid wascollected by filtration, washed with 900.0 ml of water and dried at 60°C. in vacuo to obtain 25.8 g of the mixture consisting essentially ofthe monoazo compounds with an average of twodimethylaminopropylsulfonamido moieties per molecule and having theformula ##STR16## as a red-orange-colored solid which melted at 153° to154° C.

The visible absorption spectrum of the dyestuff in a dilute acetic acidsolution containing 0.0376 g of dyestuff per liter of solution had amaximum at 490 millimicrons, A=1.328. The nuclear magnetic resonancespectrum was consistent with the assigned structure.

Paper dyed with aqueous acetic acid dilutions of this dyestuff had anorange-red shade and was found to be highly bleachable in the bleachtest described above. The dye was found to bleed moderately in the waterbleed test.

EXAMPLE 3

A. Proceeding in a manner similar to that described in Example 2, part Aabove, 40.6 g of the red pigment (4-methoxyaniline→2-hydroxynaphthalene)was interacted with 400.0 g of chlorosulfonic acid and 23.2 ml ofthionyl chloride to obtain 297.0 g of water wet pulp containing themixture consisting essentially of the monoazo compounds chlorosulfonatedwith an average of two chlorosulfonyl moieties per molecule and havingthe formula ##STR17##

The nuclear magnetic resonance of the chlorosulfonic acid solution ofthe dyestuff before isolation was consistent with the above structure.

B. In a manner similar to that described in Example 2, part B above,101.5 g of pulp from part A directly above was interacted with 30.6 g ofdimethylaminopropylamine to obtain 30.7 g of the mixture consistingessentially of the monoazo compounds with an average of twodimethylaminosulfonamido moieties per molecule and having the formula##STR18## as a red-orange solid.

The visible absorption spectrum of the dyestuff in a dilute acetic acidsolution containing 0.0376 g of dyestuff per liter of solution had amaximum at 414 millimicrons, A=0.845. The nuclear magnetic resonancespectrum was consistent with the assigned structure.

Paper dyed with aqueous acetic acid dilutions of this dyestuff had ayellow-red shade and was found to be highly bleachable in the bleachtest described above. The dye was found to bleed moderately in the waterbleed test.

EXAMPLE 4

A. A mixture of 70.0 ml of water, 40.3 g of 80 percent1-(2-aminoethyl)-2-imidazolidinone and 101.5 g of the mixture ofdisulfonylchloride monoazo dyestuffs from Example 3, part A above wasstirred overnight at ambient temperature. After stirring one hour atapproximately 60° C., the resulting solid was collected by filtration,washed with one liter of water to obtain the water wet filter cakecontaining a mixture consisting essentially of the monoazo compoundswith an average of two N-[2-(2-oxo-imidazolidin-1-yl)ethyl]sulfonamidomoieties per molecule and having the formula ##STR19##

A 10.7 g sample of the filter cake was dried at 70° C. in vacuo toobtain 3.1 g of red solid which melted at 150° to 153° C.

B. To 106.0 ml of water, 96.3 g of the water wet filter cake from part Adirectly above was added with stirring and 51.0 ml of concentratedsulfuric acid was added slowly allowing the temperature to rise toapproximately 80° C. The resulting solution was heated at reflux forapproximately 20 hours, cooled to ambient temperature and set aside overthe weekend. Slowly, the mixture was diluted with 200.0 ml of water,warmed to 40° C. and the pH adjusted to 8.0 with the addition of 90.0 mlof 50 percent aqueous sodium hydroxide. After stirring the slurry fortwo hours, the solid was collected by filtration, the filter cake washedwith one liter of water and dried in a vacuum oven at 65° C. to obtain17.6 g of the mixture consisting essentially of the monoazo compoundswith an average of two aminoethylaminoethylsulfonamido moieties permolecule and having the formula ##STR20## as a red-colored solid whichmelted at 266° to 267° C. with decomposition.

EXAMPLE 5

Proceeding in a manner similar to that described in Example 4, part Aabove, 40.3 g of the mixture of disulfonylchloride monoazo dyestuffsfrom Example 2, part A above, was interacted with 40.3 g of 80 percent1-(2-aminoethyl)-2-imidazolidinone to obtain 94.4 g of water wet filtercake containing the mixture consisting essentially of the monoazocompounds with an average of twoN-[2-(2-oxo-imidazolidin-1-yl)ethyl]sulfonamido moieties per moleculeand having the formula ##STR21## A 9.4 g sample of the water wet filtercake was dried in an air oven at 70° C. to obtain 2.5 g of soliddyestuff which melted at 163° to 166° C.

EXAMPLE 6

A. To 116.0 ml of chlorosulfonic acid, 41.5 g of Colour Index PigmentRed 41 (o-dianisidine→2 moles of 3-methyl-1-phenyl-5-pyrazolone) wasadded gradually. After stirring approximately two hours at ambienttemperature, 26.3 ml of thionyl chloride was added over ninety minutesallowing the temperature to rise to 45° C. The reaction mixture wasstirred four hours at a temperature between 45°-50° C. The mixture wasallowed to cool to ambient temperature while standing overnight. Slowly,the reaction mixture was poured onto a mixture of 2000.0 g of ice and400.0 ml of water keeping the temperature below 20° C. To the mixture,30.0 ml of xylene was added and the resultant mixture was stirred twohours at a temperature below 20° C. The separated solid was collected byfiltration and washed acid free to Congo Red test paper with cold waterto obtain 186.5 g of water wet filter cake containing a mixtureconsisting essentially of the disazo compounds chlorosulfonated with anaverage of 2.8 chlorosulfonyl moieties per molecule and having theformula ##STR22##

B. To a mixture of 27.5 g of 3-dimethylaminopropylamine and 200.0 ml ofwater chilled to 15° C. 93.2 g of the water wet filter cake from part Aabove was added slowly while maintaining a temperature between 15° to20° C. The resulting slurry was stirred overnight at ambient temperatureand then heated to 60° C. and stirred approximately one hour. The solidwas collected by filtration, washed with water until the filtrate testedneutral to Brilliant Yellow test paper and dried in vacuo to obtain 34.4g of a mixture consisting essentially of the disazo compounds with anaverage of 2.8 dimethylaminopropylsulfonamido moieties per molecule andhaving the formula ##STR23##

The visible absorption spectrum of an aqueous acetic acid solution ofthis dyestuff, containing 0.02 g of dye per liter of solution showed amaximum at 438 millimicrons, A=0.866.

Paper dyed with a dilute acetic acid solution of this dyestuff had abright yellow-orange shade and was found to be highly bleachable in thebleach test described hereinabove. The dye was found to bleed onlyslightly from paper in the water bleed test described hereinabove.

EXAMPLE 7

With stirring, 53.7 g of the red dyestuff (4,4'-diaminobenzanilide→2moles of β-naphthol) was added slowly to 200.0 ml of chlorosulfonic acidwhile maintaining a temperature between 20°-25° C. The resulting slurrywas stirred overnight at ambient temperature and slowly 23.9 g ofthionyl chloride was added. After stirring twenty-four hours at ambienttemperature, the resultant reaction mixture was added slowly to amixture of 1200.0 g of ice and 600.0 ml of water keeping the temperaturebelow 20° C. The solid was collected by filtration and washed threetimes, each with 350.0 ml of one percent aqueous sodium chloridesolution to obtain a water wet filter cake. The water wet filter cakewas added to a mixture of 300.0 ml of cold water, 41.5 g of sodiumcarbonate, 51.0 g of dimethylaminopropylamine, and 2.0 ml of pyridinewhile maintaining a temperature below 25° C. by the gradual addition ofice. The resulting slurry was allowed to stir overnight at ambienttemperature and then stirred at a temperature between 50° to 55° C. forapproximately one hour. The solid was collected by filtration, washedwith one liter of one percent aqueous sodium chloride solution and driedin vacuo to obtain 80.5 g of a mixture consisting essentially of thedisazo compounds with an average of two dimethylaminopropylsulfonamidomoieties per molecule and having the formula ##STR24##

The visible absorption spectrum of an aqueous acetic acid solution ofthis dyestuff, containing 0.02 g of dye per liter of solution showed amaximum at 489 millimicrons, A=0.875.

Paper dyed with a dilute acetic acid solution of this dyestuff had ayellow-red shade and was found to be highly bleachable in the bleachtest described hereinabove. The dye was found to bleed only slightlyfrom paper in the water bleed test described hereinabove.

What is claimed is:
 1. A mixture consisting essentially of a monoazocompound which is substituted with an average of x (N-substitutedsulfonamido) groups per molecule wherein said monoazo compound is of theformula ##STR25## in which x represents a number from 1 to 4,Rrepresents hydrogen or the moiety ##STR26## in which R⁴ is hydrogen, C₁to C₃ alkoxy or C₁ to C₃ alkyl, R¹ represents a moiety selected from thegroup consisting ofalkylene-NH-alkylene-NH₂, alkylene-N-(C₁ to C₄alkyl)₂, ##STR27## in which alkylene represents --CH₂ CH₂ -- and --CH₂CH₂ CH₂ --, R³ represents hydrogen, C₁ to C₃ alkyl or C₁ to C₃ alkoxy;orthe acid-addition salt forms of said mixtures of monoazo compounds. 2.A mixture according to claim 1 wherein the monoazo compound is of theformula ##STR28## in which R¹, R³, R⁴ and x each have the samerespective meanings given in claim
 1. 3. The mixture according to claim2 wherein R¹ is --(CH₂)₃ N(CH₃)₂ and R³ and R⁴ are each methoxy.
 4. Amixture according to claim 2 wherein the monoazo compound is of theformula ##STR29## in which R¹, R³ and x each have the same respectivemeanings given in claim
 2. 5. The mixture according to claim 4 whereinR¹ is --(CH₂)₃ N(CH₃)₂ and R³ is 2-methoxy.
 6. The mixture according toclaim 4 wherein R¹ is --(CH₂)₃ N(CH₃)₂ and R³ is 4-methoxy.
 7. Themixture according to claim 4 wherein R¹ is ##STR30##
 8. The mixtureaccording to claim 4 wherein R¹ is ##STR31##
 9. The mixture according toclaim 4 wherein R¹ is --(CH₂)₂ NH(CH₂)₂ NH₂ and R³ is 2-methoxy.
 10. Themixture according to claim 4 wherein R¹ is --(CH₂)₂ NH(CH₂)₂ NH₂ and R³is 4-methoxy.